AEMCA Practice Exam

What triggers the secretion of aldosterone from the adrenal cortex?

1. High calcium levels

2. Low potassium levels

3. Low sodium levels

4. High blood pressure

The correct answer is: Low sodium levels

Aldosterone secretion from the adrenal cortex is primarily stimulated by low sodium levels in the blood. This hormone plays a crucial role in regulating electrolyte balance and blood pressure by promoting sodium reabsorption in the kidneys. When sodium levels are low, the body needs to conserve sodium to maintain homeostasis, which leads to an increased secretion of aldosterone. The relationship between low sodium levels and aldosterone release is significant because aldosterone not only facilitates sodium retention but also affects potassium excretion; thus, it helps maintain both sodium and potassium balance in the body. While factors like high potassium levels or low blood volume can also stimulate aldosterone secretion, the specific trigger in this case is the recognition of low sodium levels, making it the correct context for this question.